I have read through various books but still have difficulty linking very simple commands together. Can someone, in really simple terms, explain the effects of these commands? Any help would be much appreciated.- ls l grep D What effect would other letter have other than D?- How id ls > list different to ls >> list?- What are the effects of these cd commands? cd / etc cd / cd~-How would I create a new directory off my root directory? -How would I create a new text file and store a few sentences in it?-How would I install the programme TREE from the command line, and use output redirection to explain what it does?-There is a line that looks like this: -rwxr-xr-x 1 root root 920788 Mar 28 2013 bashWhat does each bit mean?-What is the purpose of the bin directory?-How do I assign users a group?-How could I plan, write and test a shell script that could automate the task of creating new users and assigning them into groups.-How could have these tasks been done in a computer windows system?